Package org.apache.lucene.codecs
Class PostingsWriterBase
java.lang.Object
org.apache.lucene.codecs.PostingsConsumer
org.apache.lucene.codecs.PostingsWriterBase
- All Implemented Interfaces:
Closeable
,AutoCloseable
- Direct Known Subclasses:
Lucene41PostingsWriter
Extension of
PostingsConsumer
to support pluggable term dictionaries.
This class contains additional hooks to interact with the provided
term dictionaries such as BlockTreeTermsWriter
. If you want
to re-use an existing implementation and are only interested in
customizing the format of the postings list, extend this class
instead.
- See Also:
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionabstract void
close()
abstract void
encodeTerm
(long[] longs, DataOutput out, FieldInfo fieldInfo, BlockTermState state, boolean absolute) Encode metadata as long[] and byte[].abstract void
finishTerm
(BlockTermState state) Finishes the current term.abstract void
init
(IndexOutput termsOut) Called once after startup, before any terms have been added.abstract BlockTermState
Return a newly created empty TermStateabstract int
Sets the current field for writing, and returns the fixed length of long[] metadata (which is fixed per field), called when the writing switches to another field.abstract void
Start a new term.Methods inherited from class org.apache.lucene.codecs.PostingsConsumer
addPosition, finishDoc, merge, startDoc
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Constructor Details
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PostingsWriterBase
protected PostingsWriterBase()Sole constructor. (For invocation by subclass constructors, typically implicit.)
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Method Details
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init
Called once after startup, before any terms have been added. Implementations typically write a header to the providedtermsOut
.- Throws:
IOException
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newTermState
Return a newly created empty TermState- Throws:
IOException
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startTerm
Start a new term. Note that a matching call tofinishTerm(BlockTermState)
is done, only if the term has at least one document.- Throws:
IOException
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finishTerm
Finishes the current term. The providedBlockTermState
contains the term's summary statistics, and will holds metadata from PBF when returned- Throws:
IOException
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encodeTerm
public abstract void encodeTerm(long[] longs, DataOutput out, FieldInfo fieldInfo, BlockTermState state, boolean absolute) throws IOException Encode metadata as long[] and byte[].absolute
controls whether current term is delta encoded according to latest term. Usually elements inlongs
are file pointers, so each one always increases when a new term is consumed.out
is used to write generic bytes, which are not monotonic. NOTE: sometimes long[] might contain "don't care" values that are unused, e.g. the pointer to postings list may not be defined for some terms but is defined for others, if it is designed to inline some postings data in term dictionary. In this case, the postings writer should always use the last value, so that each element in metadata long[] remains monotonic.- Throws:
IOException
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setField
Sets the current field for writing, and returns the fixed length of long[] metadata (which is fixed per field), called when the writing switches to another field. -
close
- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Throws:
IOException
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